Tag Archives: Ps:one

I had a plan for how to blog about this project, but I’m going to step out of order and talk about the latest development since it pertains to the last Fusion 360 Meetup. So to catch up in a hurry: I’ve already constructed a control box containing an Arduino Mega 2560 and a Raspberry Pi, power supplies, relays, etc. all mounted on DIN rails. This is the “brains” of the system, and the Pi runs an open source control framework called EPICS. The control box sits on a separate stand on wheels that I welded. In keeping with the “Beer Church” theme, I suppose this is the “Beer Pulpit”.

I realized early on that the control box was out of room. I want this brewing system to be modular so that I can attach different equipment and reconfigure everything via software. To that end, each device needs to connect to the control box with its own sturdy, detachable connector. The original BrewTroller project (which isn’t online anymore) made use of XLR jacks. These are ideal. Nearly every device I’m interfacing with uses 3 or, in some cases, 2 wires. The OneWire serial bus, which is used for measuring temperatures, uses a 3 pin M12 connector; these are chained together using splitters. A few use cases need more than 3 wires: multiple pressure transducers on one board (used for fluid level sensors) and stepper motor drivers (used for controlling gas needle valves). For these, I’m using 8 pin mic connectors. But I don’t have enough panel space on the control box for all of these jacks, especially now that I’m considering adding a small touch screen. Nor do I have room inside the control box to mount a 120 V to 24 V transformer; 24 VAC is a HVAC standard, and the propane burner valves need it.

Design Sources

A number of commercially available and hobbyist-built computer controlled brewing systems already exist that solve many of the issues I mentioned in my previous post on this topic. They have a number of similarities, but address the problems in different ways. I’m going to describe a number of methods used for computer controlled beer brewing, which improve up0n repeatability by reducing deviations in the mash process. These systems range from simple thermostat / standalone PID controls to microcontroller-based devices. I’ll also list my own design decisions when building this system and my reasoning. Note that my design decisions aren’t necessarily best, there are plenty of valid arguments for and against many of the solutions presented here, and as I write this, I’m kicking myself for some of the mistakes I made along the way.

I’ve examined a number of systems. Our local homebrewing store operates one. I’ve paid particular attention to open source and published plans for hobbyists, given that these offer the most information. Two of my primary sources:

Brutus Ten – Website here. Build pages here and here. This is a popular brewing system due to plans published in Brew Your Own. It consists of a welded steel frame and propane burners driven by standalone industrial temperature control modules.

BrewTroller – The original website was oscsys.com which features an Arduino-based open software and control electronics framework for brewing. The website hosted the software, documentation, a web forum for users, and an online store where one could purchase electronics, actuated valves, switches, temperature probes, etc. It is not locked to any single brewing system design; rather, it is flexible enough to support a wide variety of brewing hardware configurations. While the original site shut down, a user took this over at this site.

Overview

A bit over a year ago, I began a project to build a computer-controlled beer brewing system that Beer Church (Pumping Station: One’s homebrew club) could use to brew all-grain beer. I had no idea when I started this project that it would lead to visiting people from multiple countries, two synchrotron radiation sources, and a nuclear research reactor, or that control systems engineers from international labs would provide assistance. While it still isn’t ready to brew beer yet, I’ve recently reached a milestone in integration testing, and I’m rapidly approaching the point where the first test batch will be possible. Unfortunately, I haven’t been blogging about it, so a lot of catching up is needed….

So, why would someone want to make what could be called a CNC machine for beer? First, it’s not about eliminating humans. The goal isn’t automation to the level of “push button, get beer.” Humans will still need to load the ingredients and monitor the process. We don’t want a hose breaking, resulting in 12 gallons of beer wort on the floor and a propane burner melting the bottom of the resulting empty stainless steel keg. Rather, the primary reasons are:

Repeatability. I want to eliminate human error. Repeatability often is the domain of commercial brewers, but for hobbyists, repeatability still is critical. Transitioning from good beer to great beer means experimentation. And that requires having good control over all the variables. How do I know if that different yeast I used made my beer taste better, or if it could be explained by sloppy temperature control in the mash process?

Predictability. Shareware and free beer design software exists that acts like CAD for beer. You can design your grain bill based on a library of ingredients, enter a mash and hop schedule, yeast, fermentation temperature, etc. and it will simulate the process, telling you what you can expect in terms of initial and final specific gravity, percent alcohol, color, bitterness, etc. You can tune the model based on the efficiency of your brewing system. But prediction works only as well as the repeatability of your process.

Capacity. Right now, we are limited to 5 gallon batch sizes. While we certainly can buy larger hardware, it makes sense to upgrade to automation at the same time. With a system based on 15.5 gallon beer kegs, we can produce 10 gallon batches at a time.

And, well, there are plenty of secondary reasons that can best be described as “Because hackerspace!” I’ve wanted to learn more about industrial control electronics and the EPICS software environment. It was a great excuse to learn to weld. I had acquired authentic cold war indicator lights from actual nuclear missile systems that needed to be put to an awesome new use. And I could do all that while brewing beer!

To describe the CNC beer system, I first need to explain all-grain brewing and the issues inherent with our current brewing method. To be clear, these issues affect repeatability, not quality. We are already making really good beer. Nothing is wrong with what we’re doing. This new system likely will improve beer clarity (and that is important in homebrewing competitions) but otherwise it won’t do much on its own to make the beer better. Start with a bad recipe and you’ll end up with bad beer; the new hardware just makes it repeatably bad! Rather, it will provide state of the art tools to anyone who wants to experiment, and this could be very useful to brewers wishing to be competitive in homebrewing contests.

Scotland is a place that, for the average American, provokes strong reactions. Single malt Scotch whisky. Haggis. And bagpipes. At least in America, the thought of 3D printed bagpipes may inspire fear in some people. Bagpipes were considered weapons of war, and commonly thought to be banned following the unsuccessful Jacobite Rising of 1745. (The Act of Proscription 1746 doesn’t directly mention them, though.) Personally, I’m quite a fan of pipe music, as well as other Scottish folk music, such as the Corries, and the music of Nova Scotia, especially Mary Jane Lamond.

I bought a Highland bagpipe practice chanter years ago, only to discover that the angle I had to hold it to keep my fingers in the right position was torture on my wrists. I figure it would be more comfortable to play when attached to an actual bag. But acquiring a full set of Highland bagpipes wasn’t terribly practical, and that would probably lead to my neighbors breaking down my door and coming after me with torches and pitchforks should I try to practice indoors. Or at least they’d complain to the condo association. So I forgot about that for a while.

Then in spring of 2014 I saw the Dreaming Pipes Kickstarter posted by Donald Lindsay of Glasgow. He was creating a 3D printed chanter with a customized extended range for the Scottish smallpipes, which are, as their name suggests, smaller, and designed to be played indoors. But he was also creating plans for a full set of smallpipes modeled off a 17th century design that could be 3D printed, with a laser cut bellows. And he was also designing 3D printed Highland bagpipe drones. I’ve got access to four 3D printers and a laser cutter at Pumping Station: One. It looked like fun to build. So I backed it.

Liquid nitrogen (LN2) rocks. Yes, officially speaking, I need to get liquid nitrogen at PS:One so that we can do serious sciencey stuff, like, say, energy dispersive X-ray spectroscopy on the scanning electron microscope. But, unofficially? Driving nails into wood with a frozen banana, or making ice cream, is just plain awesome. And the clouds of chilled water vapor billowing out of flasks like something from a mad scientist’s lab… what can I say, I’m easily amused.

First, we need a source to buy LN2. Fortunately, a very generous individual, who happens to own a really cool company that has helped us in the past with CO2 tanks and refills, and provided free LN2 to test the EDX detector on the scanning electron microscope, offered us a great deal for purchasing it. But transporting -321F liquid to PS:One and storing it presents unique challenges.

So we need to start with a large storage dewar. These can be ridiculously expensive. I scoured eBay, found one, posted a crowdfunding request to the PS:One mailing list, and, thanks to the generosity of a bunch of donors, I made the purchase.

At long last, the CNC Steampunk Harp that Elizabeth and I have been building is, at least functionally, finished! In previous posts, I documented the process of routing pockets in the side of the harp using PS:One’s CNC router, and our road trip to Sector67 in Madison, WI to use their seriously awesome laser cutter. This completed the work on all wooden parts of the harp, and so I could finally assemble it.

First, I had to glue the stiffener boards to the back of the sound board and used the drill press to make holes for the 33 strings. Gluing the sound board to the harp body required a lot of fast work: driving nails to hold the sound board in place, flipping it over and trying to wipe out the dripping glue while only having access to the inside via small holes, flipping it over to drive more nails, rinse, lather, repeat… all the while, the glue is starting to set. Then I glued the trim strips in place that covered all the nails. After that glue dried, I used a 1/4″ roundover bit on a router to clean up the sides of the sound box, and… oops! To my horror, I realized I forgot a step in the directions that said I was supposed to use extra nails to reinforce the area where the sound board joins the base near the pillar. Seeing as the harp has over 1000 lbs tension on the sound board and I really don’t want it pulling itself apart, I used the pneumatic nailer to shoot brads through the lower front trim strip. Then I needed to use wood putty to cover the brads. Oh, and did I mention that the angle of the nail gun wasn’t quite right and the brads poked through the bottom? So I had to bend them over with a nail set and cover those holes as well with wood putty. You live, you learn….

Back in October, Pumping Station: One hosted an event called Locktoberfest, an annual event run by the Chicago chapter of TOOOL (The Open Organisation Of Lockpickers.) It features, well, lockpicking, beer, and brats. (The beer is necessary to relax one’s hands. Really. I mean it.) A number of nationally known people came out to Chicago for this, including Deviant Ollam and Babak Javadi.

Lock picking involves manipulating small components. Small metal components, which are conductive, and would image well in a scanning electron microscope. And it just so happens that we’re probably the only hackerspace with a working SEM.

PS:One’s scanning electron microscope came with an Oxford Isis EDX detector that we were told was non-functional. After a little poking around, I discovered that the replacement power supply which supposedly didn’t work was shipped from London, where the default power is 240V. After changing the voltage, the computer suddenly recognized the electronics, and it passed all the self tests. That looked like a good sign, so the next step was to acquire liquid nitrogen, which is needed to cool the detector.

Fortunately, one of our members owns NFC, a company that, among other things, sells liquid nitrogen. He loaned us a dewar of LN2 so we could test it out. After transporting it back to the space, I asked Everett to watch from a safe distance and let me know if anything was spilling while I filled the dewar attached to the SEM. He took some video of the process. The plastic funnel I used was cracking as I was pouring, which in hindsight wasn’t that great of an idea, so maybe we need to find another solution here….

A few nights back, Brian and I took some images from the SEM. We exported them into TIF format, and then copied them via Sneakernet, a.k.a. using 3.5″ floppy disks and a portable USB floppy reader. I converted them into .png files. Click them for full 1024×768 resolution, the limit of the Leica image capture board. I’m very happy with how they turned out.

This is the top of a metallic pin or electronic contact, showing what appear to be machining marks as well as what looks like a good deal of surface contamination. Note the scale showing 100 microns.

Back in January, I got word that Philip Strong, a past member of PS:One, worked for a company that needed to get rid of a working scanning electron microscope and was considering donating it to PS:One. While PS:One has an existing SEM in the space (a Leica S440, owned by JP, a member), this one supposedly was fully functional, had documentation, and we could get some help from the microscopist, Susan Young, who used it. Of course we were interested!

On Monday the 18th, I learn that yes, the donation was approved, but with a catch: It had to be moved on Saturday the 23rd!